'Shark Tank' Star Robert Herjavec ... Dating 'DWTS' Partner Kym Johnson

"Shark Tank" star Robert Herjavec has a new asset in his portfolio -- his "Dancing With the Stars" partner Kym Johnson ... and she gets an awesome gift from him if they win.

Herjavec and Johnson met mid-February right before the "DWTS" cast was announced ... and we're told they started dating immediately.

They spent Saturday night at a party in the Hollywood Hills and Monday at Hyde lounge with the "DWTS" cast. Our spies tell us they're very open about the relationship ... lots of making out.

Herjavec has also promised Johnson if they win "DWTS" she'll get one of his Ferraris.

We broke the story earlier this month Herjavec and his wife of nearly 25 years had separated and were heading for divorce.

Things move quickly with Bob.